Sewage systems remove waste via flow of water and other entrained material through pipes to sewage treatment plants. Generally, the flow is moved in a desired direction by arranging the pipes so that gravity draws the flow “downhill.” At times assistance is provided by sewage pumps, for example, to urge flow along and/or to lift flow to a higher level where gravity based flow starts again. Such pumps may be located in a structure along the sewer line in structures commonly known as a wet well, a lift station, or a pumping station.
Such pumps are electrically operated and are often automatically turned on and off by sensors such as float switches, proximity switches, probes, or the like. For example, when a sensor notes that material in a pumping station has reached a first predetermined (full) level, the pumps operate to pump out the material. During pumping, when another sensor notes that material has fallen to a second predetermined (empty) level, the pumps cease operation. Even at an “empty” level in the pumping station, some material remains as the pump inlets are arranged so as to remain under the surface of the liquid to prevent malfunction. This operation continues and the pumping station is sequentially filled by flow and then pumped out by the pumps.
Sewage contains various substances, such as waste, fats, greases, grit, and slime, etc. Some of such substances will float on top of the liquid in the pumping stations and therefore not reach the pump inlets. The substances can build up over time requiring chemical treatment and/or regular mechanized or manual removal. Such substances can also form hardened conglomerations over time. Such masses may eventually block pump inlets, or may be drawn through the inlets into the pumps, thereby causing clogging or damage. Fats and greases, for example, are known to float and collect into large somewhat solid clumps that can be problematic in this way.
Accordingly, improvements in pumping stations that provide more reliable and/or less labor-intensive operation addressing one or more drawbacks of current systems or other issues would be welcome.